/*
 * Copyright (C) 2012 by Zhang Li <RichSelian at gmail.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include "nw-allocator.h"
#include "nw-exception.h"

nw_allocator_t* nw_allocator_create(size_t poolsize) {
    nw_allocator_t* nw_allocator;

    if((nw_allocator = malloc(sizeof(nw_allocator_t) + poolsize)) != NULL) {
        nw_allocator->m_ptr_head = nw_allocator->m_pool_data;
        nw_allocator->m_ptr_tail = nw_allocator->m_pool_data + poolsize;
    }
    return nw_allocator;
}

void* nw_allocate(nw_allocator_t* allocator, size_t size) nw_throws(nw_allocate) {
    unsigned char* ptr = allocator->m_ptr_head;

    if(size >= allocator->m_ptr_tail - allocator->m_ptr_head) {
        nw_throw(E_ALLOCATE);
    }
    allocator->m_ptr_head += size;
    return ptr;
}

void nw_allocator_freeall(nw_allocator_t* allocator, size_t size) {
    allocator->m_ptr_head = allocator->m_ptr_tail - size;
    return;
}

void nw_allocator_destroy(nw_allocator_t* allocator) {
    free(allocator);
    return;
}
